In order to convey a strip-shaped cast piece (slab) drawn out of a mould, a continuous casting installation is provided with a roll apparatus in which several to several tens of segments, each having a plurality of roll bodies, are arranged in a conveying direction.
The roll body of this roll apparatus is deflected in a radial direction by a high load applied thereto from the slab side. Therefore, is rotatably supported by a rolling bearing with aligning housing ring so as to absorb this deflection. Also, the roll body is thermally expanded in an axial direction by heat transferred thereto from the slab. Therefore, one axial end thereof is supported by a self-aligning roller bearing in an axially-restrained (fixed) condition, while the other axial end thereof is supported in an axially-movable condition by a cylindrical roller bearing with aligning housing ring in which inner and outer rings are movable relative to each other (see Japanese Patent Publication No. 61-229453A).
However, in the fixed-side self-aligning cylindrical roller bearing, two-peak wear due to differential slip is liable to develop on a raceway surface because of its structure. The two-peak wear invites damage such as separation since stresses concentrate on peak portions of the raceway surface. Therefore, it can become the cause of a lowered durability of the bearing. The roll apparatus of the continuous casting installation is formed by arranging several to several tens of segments (each comprising the plurality of roll bodies) in the conveying direction. Therefore, when one of the self-aligning roller bearings is damaged, the whole of the relevant segment must be replaced, and the rate of operation of the installation is considerably lowered.
In order to solve the problem encountered with the above self-aligning roller bearing, it is proposed in Japanese Patent Publication No. 10-68415A to use a combination of a cylindrical roller bearing with aligning housing ring and a deep groove ball bearing as a rolling bearing device for supporting the fixed side of a roll body. Namely, in this technique, the cylindrical roller bearing mainly receives a radial load from the roll body, and the deep groove ball bearing receives an axial load from the roll body, thereby restraining an axial movement of the roll.